I always want to translate Värdefull as wonderful =).
Värde means ’value, worth’ if that helps you remember.
Tack! It really helps: in Ukrainian there is 'варто' (pronounced as 'varto') that means 'worth'.
It's very like the Dutch 'waard' and here 'waardevol'.
So literally, "worthful books"?
The german equivalent for 'värderfull' is 'wertvoll', which, in both cases can be thought of as full of value.
I think Emil is looking for these, isn't he? :) #ssss
Does värdefulla mean that they are monetarily valuable AND that they are instrinsically valuable in some other way?
It definitely means "monetarily valuable", I'm not certain if it'd sound natural if you're referring to sentimental value.